On Wed, Apr 02, 2008 at 11:12:44AM +0200, Harald Schmalzbauer wrote:
> Hello,
> I have severe problems with my optical drive(s) support.
> The drive is on an ICH9 in AHCI mode.
> I tested different writers, all show the same problem.
> When the system boots with a CD in the drive or if I mount the acd0 device
> I see acd0: FAILURE - READ_BIG MEDIUM ERROR asc=0x11 ascq=0x05
> or:
> acd0: FAILURE - READ_BUFFER ILLEGAL REQUEST asc=0x24 ascq=0x00

Are the errors harmful? Historically these errors haven't been. You
state later "burncd doesn't work, but cdrecord does". The errors appear
to indicate that certain ATAPI commands are being rejected by your drive
(or possibly due to the physical medium inserted in it).

I'd try Googling for "freebsd sata ILLEGAL REQUEST" and see for

Linux's kernel reports similar errors, though in a different way, since
they use an ATA-to-SATA conversion driver for hard disks and CDROMs:


> When I mount the drive with /dev/cdX (atapicam) I don't see any error!

Possibly atapicam(4) isn't using those ATA commands, or is hiding the
errors from you.

> burncd fails completely, cdrecord seems to work.
> I don't understand why the scsi path to the drive is working while the
> (native) atapi path is broken...

| Jeremy Chadwick jdc at parodius.com |
| Parodius Networking http://www.parodius.com/ |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |

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